1. Field of the Invention
The present invention relates to a novel improvement in battery monitors by which an individual cell of a wet cell battery may be monitored for variations in the state of charge of the electrolyte and electrolyte level. More specifically, it relates to a monitoring device which may be utilized in conjunction with emergency wet cell batteries already on location or in use for emergency backup power sources.
2. Description of the Prior Art
The prior art is replete with systems for remote indication of the specific gravity (state of charge) of battery electrolytes. For example, U.S. Pat. Nos. 4,124,739 and 3,508,973 typify this art. Specifically, when the state of charge of a given electrolyte drops below a certain level, a monitoring device sets off some sort of warning signal
The prior art is likewise significant in the area of electrolyte level (fluid height) indicators. Thus U.S. Pat. Nos. 3,996,579; 3,366,943; 2,534,633 and 2,471,660 all describe systems for measuring battery electrolyte level drops wherein probes are inserted into one or more cells and when the level of fluid drops below the minimum acceptable level (predetermined depth of the probe) a circuit is completed so as to signal an alarm.
U.S. Pat. Nos. 4,388,584 and 3,600,234 both describe systems which monitor state of charge and electrolyte level. However, neither of these systems are designed to be portable units which may be moved from battery to battery as is the present invention. More significant, the devices rely upon either voltage regulation without the blocking diodes system of the present invention or more complicated systems involving transistor/zener diode combinations. Also in the present invention system a burden is placed on the battery that is being monitored since the present invention probe is used as a current carrier, unlike the prior art systems which are being used merely to check continuity or voltage.
There are some teachings in the prior art with respect to the use of tungsten carbide electrode accumulators and tungsten/platinum probes to create potential differences, such is taught in German Pat. No. 2,454,410 and British Pat. No. 790,419, respectively. But this prior art does not teach the use of a purely tungsten probe nor does it teach the use of such a probe in the context of the present invention as more fully described below.
Thus, notwithstanding the relatively close prior art in this particular field of technology, it is believed that the prior art neither teaches nor renders obvious the unique, dual purpose emergency wet cell battery monitor of the present invention.